【作者】 苏卫卫；

【导师】 佟琦； 韩宝航；

【作者基本信息】 燕山大学 ， 化学工程（专业学位）， 2021， 硕士

【摘要】 近年来,已经涌现出大量的分析表征手段,其中,由于荧光光谱技术具有高灵敏度、操作简便以及时空分辨率强等优势,已经引起众多的关注。光的发射,本质上是由于电子的跃迁,光子撞击电子并提供一些能量。激发态的到达源于反应物中一种特殊的官能基团对某一特定波长的光子的吸收。当到达激发态后,光子把自身的能量直接地传递到荧光目标分子中,从而产生荧光发射现象。荧光材料作为一类新兴的具有优越光学特性的材料,其空间构型、构象、拓扑结构以及聚集态等结构的多样性赋予了荧光发射的多样性。基于此,荧光材料在光谱表征方面发挥着重要应用,其中,荧光探针尤其受到广泛关注。采用改进的Hummers法合成了具有优异的光学、电学及力学特性的氧化石墨烯（GO）,随后,运用还原反应对GO加以表面修饰,制备了苯硼酸功能化还原氧化石墨烯（rGO-PBA）。采用传统的水热合成法,合成了多羟基碳点（CD1）,用于后续的荧光探测。该法操作简便,成本低廉。利用苯基硼酸在水性介质中可与二醇快速可逆地反应特性,设计了基于CD1的rGO-PBA用于葡萄糖的传感检测。当CD1靠近rGO-PBA的表面时,碳点的荧光发生淬灭。然而,随着葡萄糖的不断加入,碳点的荧光不断增强,并且与葡萄糖的浓度呈良好的线性关系,起到良好的检测效果。运用罗丹明（RhB）与乙二胺（EDA）进行缩合反应,制备了罗丹明-乙二胺（RhB-EDA）荧光探针用于检测Fe³⁺。纯的RhB染料在500-600 nm之间有明显的紫外峰的凸起,而合成的RhB-EDA荧光探针在此处基本无峰出现。然而,随着Fe³⁺的加入,荧光发射强度增加,并且紫外吸光度也有所增高。同时,还会出现裸眼可见的粉红色。为了对荧光发射现象进行进一步探索,解决传统生色团易漂白、不稳定等限制,本文设计制备了不具备传统生色团的天然生物大分子荧光水凝胶。其间,探讨了浓度、p H以及老化时间等外界因素对水凝胶特殊荧光发射的影响。发现其荧光不仅显示明显的聚集诱导效应,而且还发现一种特殊的发光现象,即荧光发射倾向于向红色边缘移动,并且荧光强度随着激发波长的变化而降低。更多还原

【Abstract】 Up to this day,a large number of analytical and characterization methods have emerged.Among them,fluorescence spectrometry has attracted much attention because of its high sensitivity,simple operation and strong spatio-temporal resolution.The emission of light is essentially due to the transition of electrons,and photons hit the electrons and provide some energy.The special functional groups of reactants absorb photons with certain wavelength to reach the excited state,and then the photons transfer their own energy directly to the target molecules,so that fluorescence emission occurs.As a new kind of materials with excellent optical properties,the diversity of spatial configuration,conformation,topological structure and aggregation state of fluorescent materials endows the diversity of fluorescent emission.Based on this,fluorescent materials have been playing an important role in spectral characterization,especially fluorescent probes.Graphene oxide（GO）with excellent optical,electrical and mechanical properties was synthesized by improved Hummer method.Then,GO was modified by redox reaction,and phenylboronic acid functionalized reduced graphene oxide（rGO-PBA）was prepared.Polyhydroxy carbon dots（CD1）were synthesized by the traditional hydrothermal synthesis method,which was used for subsequent fluorescence detection.This method is easy to operate,low in cost and popular.Accord to that characteristic that phenylboronic acid can react with diol rapidly and reversibly in aqueous medium,rGO-PBA based on CD1 was design for glucose sensing detection.When CD1 approaches the surface of rGO-PBA,the fluorescence of carbon spot was quenched.However,with the continuous addition of glucose,the fluorescence of the carbon spot increases continuously,and has a good linear relationship with the concentration of glucose,which has a good detection effect.A rhodamine-ethylenediamine（RhB-EDA）fluorescent probe was prepared for the detection of Fe³⁺by condensation reaction between RhB and EDA.The pure RhB dye has an obvious ultraviolet peak bulge between 500-600 nm,while the synthesized RhB-EDA fluorescent probe basically has no peak here.However,with the addition of Fe³⁺,the fluorescence emission intensity increased,and the ultraviolet absorbance also increased,and at the same time,the naked eye can see pink.In order to further explore the phenomenon of fluorescence emission and solve the limitations of traditional chromophores,such as easy bleaching and instability,natural biomacromolecule fluorescent hydrogels without traditional chromophores were designed and prepared in this paper.Meanwhile,the effects of external factors such as concentration,p H and aging time on the special fluorescence emission of hydrogel were discussed.It was found that the fluorescence not only showed obvious aggregation induction effect,but also showed a special luminescence phenomenon,that was,the fluorescence emission tended to move to the red edge,and the fluorescence intensity decreases with the change of excitation wavelength.更多还原